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Example
This example shows how PPO type 1 is used for
changing the ramp-up time (parameter 207) to
10 seconds and for commanding a start and speed
reference of 50%.
PPO. Parameter-Process Data Object
PCD:
Process Data
PCV:
Parameter-Characteristics-Value
PCA:
Parameter-Characteristics (Bytes 1, 2)
PCA handling below
IND:
Subindex (Byte 3), (Byte 4 is not used)
PCV
PCV
PCV
PCV
PCV
PCA - Parameter Characteristics
15 14 13 12
11
10 9 8 7 6 5 4 3 2 1 0
RC
SMP
RC:
Request/respons Characteristics
SPM:
Toggle-Bit for Spontaneous Messages
PNU:
Parameter #
PCA part (byte 1-2)
The R
C part
tells what the PCV part must be used for.
The functions available appear from the table, page
17.
When a parameter is to be changed, choose value 2
or 3, in this example 3 is chosen, because parameter
207 covers a long word (32 bits).
MG.90.A2.02 – VLT is a registered Danfoss trademark
FCM 300 PROFIBUS / VLT 2800 PROFIBUS
SPM bit:
The function is explained on page 19, in the example
the function Spontaneous Messages is not applied
(parameter 917 = OFF), therefore SPM is set for 0.
PNU = Parameter number:
PNU
Parameter number is set for: 207 = CF Hex.
(Range: 0..15)
This means that the value of the PCA part is 30CF
Hex.
(Range: 1..1999)
IND (bytes 3-4):
Used when reading/changing parameters with
subindex, for example parameter 915. In the example
bytes 3 and 4 are set for 00 Hex.
PVA (bytes 5-8):
The data value of parameter 207 must be changed to
10.00 seconds. The value transmitted must be 1000,
because the conversion index for parameter 207 is
-2, this means that the value received by VLT is
divided by 100, making VLT perceive 1000 as 10.00.
Bytes 5-8 = 1000 = 03E8 Hex.
PVA:
Parameter value (Bytes 5 to 8)
CTW:
Control word
STW:
Status word
MRV:
Main reference value
MAV:
Main actual value
see page 22
23
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